Heavy rain fell across Montgomery County and caused widespread poor drainage flooding on the 2nd and stream and river flooding on the 2nd and 3rd. Rain started late in the evening on the 1st and continued throughout the day on the 2nd. The rain fell at its heaviest during the afternoon of the 2nd. The rain tapered off to some spottier light rain or drizzle during the evening and overnight and ended during the morning on the 3rd. Storm totals ranged between 2.5 and 4.5 inches. The heavy rain and flooding caused the closure of River Road near Pennsylvania State Route 309 in Fort Washington. Four roads were closed due to stream flooding in Upper Moreland Township. Several roads were also closed in Hatboro Borough. Seven gaged sites on streams and rivers flooded within the county and flooding was also reported along the Pennypack Creek.  The Schuylkill River at Pottstown was above its 13 foot flood stage from 930 a.m. EDT through 912 p.m. EDT on the 3rd. It crested at 13.41 feet at 430 p.m. EDT. The East Branch of the Perkiomen Creek at Schwenksville was above its 7 foot flood stage from 443 p.m. EST on the 2nd through 525 a.m. EDT on the 3rd. It crested at 10.42 feet at 1 a.m. EST on the 3rd. The West Branch of the Perkiomen Creek at Hillegass was above its 5 foot flood stage from 525 p.m. EST on the 2nd through 1205 a.m. EST on the 3rd. It crested at 5.28 feet at 645 p.m. EST on the 2nd. Along the main stem of the Perkiomen Creek at East Greenville, the creek was above its 4 foot flood stage from 4 p.m. EST on the 2nd through 1 a.m. EST on the 3rd. It crested at 5.98 feet at 9 p.m. EST on the 2nd. Farther downstream, at Graterford, the Perkiomen Creek was above its 11 foot flood stage from 507 p.m. EST on the 2nd through 727 a.m. EDT on the 3rd. It crested at 14.18 feet at 1 a.m. EST on the 3rd. The Wissahickon Creek at Fort Washington was above its 9 foot flood stage from 432 p.m. EST on the 2nd through 1251 a.m. EST on the 3rd. It crested at 12.62 feet at 9 p.m. EST on the 2nd. The Manatawny Creek at Pottstown was above its 6 foot flood stage from 427 p.m. EST on the 2nd through 318 p.m. EDT on the 3rd. It crested at 8.26 feet at 4 a.m. EDT on the 3rd. Specific storm totals included 4.50 inches in Palm, 4.40 inches in Wynnewood, 3.52 inches in Pottstown, 3.35 inches in Blue Bell, 3.27 inches in Norristown, 3.00 inches in Hatboro and 2.63 inches in Eaglesville.    The flooding heavy rain was caused by a low pressure system that moved from the southern Gulf Coast States on the morning of April 1st northeast to the eastern Tennessee Valley during the evening of the 1st, to far western Virginia just after Midnight EST on the 2nd, into central Virginia at 7 a.m. EST on the 2nd, near Washington, D.C. at 1 p.m. EST on the 2nd, near Lancaster, Pennsylvania at 7 p.m. EST on the 2nd, near Scranton, Pennsylvania at 1 a.m. EST on the 3rd, over the Finger Lakes in New York at 8 a.m. EDT on the 3rd and into eastern Lake Ontario at 2 p.m. EDT on the 3rd. The strong southeast flow preceding the low pressure system was able to entrain Atlantic Ocean moisture in addition to the Gulf of Mexico moisture into the system. The flooding was exacerbated by the already wet soil conditions due to heavy rain on both March 23rd and 28th.

Flood in MONTGOMERY, PENNSYLVANIA
From 02-APR-05 16:00:00 to 03-APR-05 20:12:00 (EST)
Reported by: AWOS,ASOS,MESONET,ETC